Video surveillance often utilizes video cameras for viewing a scene, such that video images from the scene can be recorded and/or provided to displays monitored by security personnel. One problem is that when a video camera is accidental moved or covered (or intentional tampered with) the camera can become an invalid camera as it is no longer properly viewing the intended scene under surveillance, and can thus pose a security risk. Traditionally, video surveillance relies on security personnel to identify the occurrence of an invalid camera, but such reliance can cause delay when security personnel are not actively engaged in video monitoring, or are viewing a large number of video displays simultaneously at a workstation or console. The sooner an invalid camera is detected the lower the risk that video surveillance, and security provided by such surveillance, can be compromised.